I used to run a Z Corp machine. I hated it. Expensive and the parts were so fragile. Good for white models though. The texture actually simulates a heavy sand mold texture which is nice. Unfortunately that is 1% of what I need to prototype.
Nice to see some people trying to breath new life into these though. It was cool technology. Butt simple. It makes you bang your head and say, “why didn’t we have 3D printers in 1976!”.
I remember having the same error while running all of their proprietary materials. If I remember correctly, it was either the rails were too dusty or the head station was not clean enough. You have to practically hand polish the inside of this thing after every print.